System of distribution for direct current.



No. 889,911. PATENTED JUNE 9, 1908.

P. DARLINGTON.

SYSTEM OF DISTRIBUTION FORDIRECT CURRENT.

APPLICATION FILED JUNE 25, 1906.

Fig. 7.

lllllllll machines, which serve asmotors,

. erably insulated therefrom and UNITED s ipiEs arana? caries.

FREDERlCK DARLIXGTOX, ()l PITTSBL'RU, PENNSYLVANIA, ASSIGXUR TU \YJISTINGHOUSE ELECTRIC it BIAXFlfrlU'lUliIXG (JOUIAXY, A CORPORATION OF PENNSYLVANIA.

SYSTEM OF DISTRIBUTION FOR DIRECT CURRENT.

Specification of Letters Patent.

Patented June 9, 1908.

Application filed June 25, 1906. Serial No. 323,368.

To all whom it may concern:

Be it known that I, FREDERICK DARLING- TON, a citizen of the United'Sates, and a resident of Pittsburg, in the county of Allegheny '5 and State of Pennsylvania, have invented a i new and useful Improvement in Systems of hDistribut-ion for Direct Current, of which the following is a specification.

' I My invention relates to systems of electrical distribution, and particularly to systems for supplying direct current to'electrio railwaymotors and other translating devices.

' The object of my invention is to provide means wherebythe distribution of direct current to railway and other systems at comparatively high voltages and the utilization thereof by translating devices at lower voltages' may be effected. The maximum voltage at which direct current may be supplicdf-to motors depends upon-the voltage to which the insulation ma be safely subjected, and upon that at whic successful commutation'may be effected.

In railway or other motors that are sub- I jc'cted to severe service, the former condition usually controls, thou h both conditions may render it impractical) e to apply more than I six or seven hundred volts to the motors, which low voltages, however, cannot be eco nomically transmitted over long distances.

According to the present invention, I pro i pose to provide railway vehicles with two or more dynamoelectric machines that are i coupled together and areconnected in series "relation, and to connect the ropelling mo- T -tors for the vehicles between t .e terminals of one or more of the machines, the remaining being preffrom other :parts. The voltage of the distributing system may then beequal tothe sum of the voltages of the individual machines, while that applied to the pro elling motors will be thefvo tageof the machine or machines be- ,tween the terminals of which they are con rnected. If the mOt O the motorigenemwr 1 setare placed in the circuit nearest thetrolley conductor and are insulated from the genera- I i tors and from the earth, the strains upon the insulationof the machines may. not be excessive, eapeciallysince they are subjected to has severe service than the repelling motors Jmd'anay ais'o he more see y insulated.

a diagrammatic view of a system that embodies my invention. Fig. 2 a diagram of a modification of the system of Fig. 1, and Fig. 3 is a diagram of anothenmodification of the invention.

Connected in series relation between the distributing conductors of an electrical circuit, such as a trolley conductor 1 and a track rail 2, are dynamo-electric machines 3 and 4,

the former of which is adapted to operate as a motor and the latter as a generator. and the rotatable armatures 5 and 6 of which are me chanioally connected by means of a 7. Field magnetwinding's 8 and dynamo-electric machines may be connected in shunt relationto the armatures thereof, and the field strengths may be adjusted by means of rheostats 1'0 and 11.

Connected between terminals of the .machine4 are a. plurality of translating devices 12, such as the propelling motors forth'e vehicle. In operation, current is supplied to the motors 12, both from the distributing circuit and from the generator 4, and consequently' the generator need be of capacity motor 3 and the generator 4. Since the v01- tageapplied to the motors 12 will depend upon the s eed .of rotation of the armature Figure 1' of the accompanying drawings is con ling 9 oi the sufficient to supply only half of the current that of the generator. The voltage applied and upon t e field strength of the generator,

the rheostats 10 and 11 ma be employed to effect variation thereof. The generator 4 and the motors 12 being arranged nearest the grounded side of the circuit, little or no danger, exists of applying excessive voltages thereto and of thus subjecting the insulation thereof to abnormal strains! In order to relieve the strain upon the insulatin b10ck'15 may be placed between the parts 0 the coupling 7, the'ma'chine being in this mannen. entirely insulated .from the 'ground and from the remaining machines e rcept through the series connection.

sulation of the motor 3, it may be mounted. upon insulating blocks 13 and 14 and an in-.

A distinct advantage that may be derived from the employment of the system of the present invention over other motor-generator systems of distributiop, is that the ca acity of each of the machines 3 and 4 need )e but approximately half the aggregate capacity of the translating devices 12, while in other systems each machine must have substantially the same capacity as the aggregate capacity of the translating devices. It will, of c=. urse, be understood that the voltages applied to the individual propelling motors may also be varied by changing the circuit relations thereof, as by changing them from serir to parallel relation, or from series to series-parallel relation, etc.

It may be desirable, in many cases, to adjust the field strengths of the motor and generator simultaneously, and accordingly in Fig. 2 I have shown field magnet windings 16 and'l? of machines 18 and 19, respectively, as connected in series relation, with a rheostat 20 between the trolle conductor 1 and the track rail 2. The fie d strength of the generator may also beadjusted independently of that of the motor 18 by means of a rheostat 21 connected in'shunt relation to the field magnet winding 17.

In order to provide for the application of a greater range of voltages to the propelling motors of a vehicle and also the utilization of a higher voltage between the trolley conductor and the track rail, a greater number of machines than two may be employed in the motor-generator set, as shown in Fig. 3, in which armatures of motors 22 and 23 are mechanically connected to armatures of gen erators 24 and 2-5 by means of a coupling 26, motors 27 being connected, in suitable circuit relations with respect with each other, between the terminals of either generator, or between the outer terminals of both generators, as desired. The strains upon the insulation of the motors 22 and 23 may be relieved by insulatingthem from the generators 2 and 25 by means of an insulating block 28 placed between the arts of the coupling 26, and by mounting the frames upon insulating blocks 29. If desired, the motors 22 and 2} may also be insulated from each other in a similar manner to that in which the motors are insulated from the generators. Field magnet windings 30, Ill, 32 and 33 of the ma chines ZZZ to 25, inclusive, are connected respectively in shunt to the correspmnling arnmtures, and the field strengths may be adjusted indi-lpt-mlohtlj' of one another by means of rlw d'ats 34, I55, 36 and 37, though, of course, the field (g arranged in other suitable relations, and the iield strengths may be adjusted by other suitable means.

The invention may be employed with other numbers of mar-hint if desired, and the arr-alignments and vi. connections gnet w ndings may he 1 thereof may be varied within considerable of the invention or the result secured by it, I and I desire that all such modifications shall be included within its scope.

I claim as my invention:

1. The combination with two or more d namo-electric machines mechanically coup ed together and electrically connected in series relation, of a translating device connected between terminals of one or more of the machines, and means for insulating one or more of the machines from the'others and also from the ground.

2. The combination with two or more (1 *namo-electric machines mechanically coup ed together and electrically connected in series relation, of a translating device con- ,nected between the terminals of one or more of the machines, and means for similarly and simultaneously varying the field strengths of the machines.

3. The combination with two or more d namo-electn'c machines mechanically coup ed together and electrically connected in series relation, and field magnet windings therefor connected in series relation, of means'for similarly and simultaneously adand a translating device connected between the terminals of one or more of the machines.

4. The combination with one or more motors and one or more generators mechanic ally coupled to ether and electrically connected in series elation, of a translat ng device connected betwcen the terminals of one or more of the "encrators, the motor or motors being insulated from the generator or generators and from the ground.

The combination with two or more dvnamoclectric machines mechanically coupled togetherf and electrically connected in series relation, of means for similarly and simultaneously adjusting the field strengths of the machines, means for-independently adjusting the field strength of at least one of the machines, and a translating device connected between the terminals of one or more of the machines.

6. The combination with two or more dvnamo-electric machines mechanically couplcd together and electrically connected in Z series relation, and held magnet windings therefor connected in series relation, of l means for similarly and simultaneously adl justing the field strengths of the machines, i means for independently adjusting the field strength of at least one of the machines, and j a translating device connected between the l terminals of one or more of the machines.

l l l l 7. The combination with two or more d name-electric machines mechanically coupled together and electrically connected in series relation, and field magnet windings therefor connected in series relation, a varilimits Without altering the mode of operation justing the field strengths of the machines,

' able resistance in series with the field magsubscribed my name this 15th .day of June,

net wl'n'dxngs, a vai-mblo. reslstance 1nde- 1906.

mydentLV associated-vim the field magnet FREDERICK D winding 01 one of the machines, and a trans-.

I 5 l ating device connected between the termi- \Vitnes'ses: I

nnls of one. or more of the machme's. I} OTTO b. SCHAIRER, 1n testlmony'whereqf, l have. hereunto BIRNEYSHINESJ 

